Method and apparatus for pumping a liquid and compressing a gas

ABSTRACT

The method and apparatus for pumping liquid and compressing a gas which includes the utilization of a pump, a compressor and a reservoir with the liquid and gas circuits being interconnected so that the pump handles a two-phase fluid for delivery to the reservoir with the two-phase fluid consisting of liquid from a supply and gas and liquid fed back from the reservoir to maintain a liquid level therein. Gas is fed to the compressor from a supply and also selectively from the area of reservoir above said liquid level to maintain a selected gas pressure therein and liquid and gas from the compressor are separated with the liquid being fed back to the pump.

United States Patent Aronson Dec. 30, 1975 METHOD AND APPARATUS FOR PUMPING A LIQUID AND COMPRESSING A GAS [21] Appl. No.: 476,673

3,824,040 7/1974 Aronson 417/503 Primary ExaminerWilliam L. Freeh Assistant ExaminerG. P. LaPointe Attorney, Agent, or FirmEugene E. Geoffrey, Jr.

[57] ABSTRACT The method and apparatus for pumping liquid and compressing a gas which includes the utilization of a pump, a compressor and a reservoir with the liquid and gas circuits being interconnected so that the pump [52] f 417/54; 137/209; 417/204; handles a two-phase fluid for delivery to the reservoir 417/295 with the two-phase fluid consisting of liquid from a [51] Int. Cl. F04B 23/10; HOlV 1/30 Supply and gas and liquid fed back from the reservoir [581 Fla! of Search 117/199 to maintain a liquid level therein. Gas is fed to the 417/295; 137/2075, 209, 2 compressor from a supply and also selectively from the area of reservoir above said liquid level to main- [5 6] References cued tain a selected gas pressure therein and liquid and gas UNITED STATES PATENTS from the compressor are separated with the liquid 1,664,276 3/1928 Williams 137 2075 being fed back to the P pl,986,003 l/l935 Lum 3,565,550 2 1971 Bellmer 417 204 21 Clam, 12 D'awmg liq/VA Z4 :5 4mm 6 ,wwrs 2 ,162, ffffif' Ms/my I 1442 V5 {POP V41 Vt) f y F6 #2 ill 217 W J I 26 2/ 645 l J6 PIP/M) swim/v 42%?16 PM, W raw/e04 c 615 Q? U Mao/mi M ==L .m'o/vmr Mr V 045 flow V62 i i i PO/Pr i /4 l //7 a 40mm; Ms A/QZl/fl [fl 2 51% gig 6 L. 211.3 it? l=-= 64s mMP/msszw 3/ 544/465 a f? z j 3/) cram E (IE/3W4 OVEFFLUIV Pin/AW 11/ 0/4 1 MAW/z US. Patent Dec. 30, 1975 Sheet 1 of7 3,929,399

US. Patent Dec. 30, 1975 Sheet 2 of7 3,929,399

US. Patent Dec. 30, 1975 Sheet 3 of7 3,929,399

US. Patent Dec. 30, 1975 Sheet 4 of? 3,929,399

US. Patent Dec. 30, 1975 Sheet 5 of7 US. Patent Dec. 30, 1975 Sheet 6 of7 3,929,399

US. Patent Dec. 30, 1975 Sheet 7 of7 3,929,399

METHOD AND APPARATUS FOR PUMPING A LIQUID AND COMPRESSING A GAS This invention relates to compressors and pumps and more specifically to a novel and improved method and apparatus for pumping a liquid and compressing a gas and effecting precise control of the output liquid and gas pressures and at the same time delivering substantially liquid-free gas and gas-free liquid.

Combination compressor-pump structures have been suggested including structures utilizing vane-type devices such as disclosed in, US. Pat. No. 3,860,364, issued Jan. 14, 1975 entitled PUMP-COMPRESSOR SYSTEM; and US. Pat. No. 3,824,040, issued July 16, 1974, entitled FLOATLESS CONTROL OF LIQUID LEVEL, ESPECIALLY USEFUL IN ATOMIZING SYSTEMS. This invention constitutes an improvement of the devices of said applications in that it embodies an improved structure utilizing a self-contained reservoir cooperating with both the pump and compressor for receiving a two-phase fluid, separatingthe liquid from the gas and delivering liquid at a predetermined rate. Improved feed back controls in both the pump and compressor systems together with regulated coupling of the liquid and gas systems affords wholly self-contained apparatus for delivering precise quantities of gas and liquid and is useful among other things for supplying air and oil for heating purposes, gases and fuels for engines and other similar applications.

Another object of the invention involves a novel and improved compressor-pump for simultaneously pumping a liquid and compressing a gas wherein a plurality of liquid inlet ports are provided with at least two inlet ports being interconnected with both the gas and liquid outlet circuits for controlling the liquid supply rate and reprocess leakage liquid in the gas supply Still another object of the invention resides in a novel and improved pumping system for liquids and gases wherein the liquid pumping means includes a plurality of inlet ports positioned at different points of the pumping cycle for recirculation of liquids and the coupling of the gas pumping means with the liquid pumping means for cooperation therebetween to control liquid pressure.

Still another object of the invention resides in a novel and improved pump compressor and reservoir combination including interconnections therebetween for supplying controlled quantities of gas and liquid wherein the specific rates of delivery of each fluid can be readily adjusted to meet specific applications.

Still another object of the invention resides in the provision of a novel and improved liquid pumping and gas compressing system wherein liquid and gas outlets are interrelated and fed back to inlets on the pump to effect precise control of the rate of delivery of liquid and to control the supply of liquid to the pump to prevent flooding of the system.

A still further object of the invention resides in the provision of a novel and improved system for deliverying a gas and a liquid at precise rates of flow.

A further object of the invention resides in the provision of a novel and improved pump and compressor combination.

The invention involves both an improved pump and compressor combination contained effectively within a single housing and including a reservoir interconnected with the pump and compressor and a novel and improved liquid pumping and gas compressing systems wherein said pump includes a plurality of inlets at spaced pressure points in the pumping cycle, a reservoir for receiving both gas and liquid and feeding both gas and liquid to one of said pump inlets to maintain a given liquid level in the reservoir, a coupling between said pump and compressor through said reservoir and a coupling between the outlet of the compressor and a pump inlet for feeding. back liquid contained in the air by reason of the inter-relationship of the pump and compressor combination and means for regulating the feed back of gas from the reservoir to the compressor for controlling the rate of liquid delivery independently of the output of air pressure.

The above and other objects and advantages of the invention will become more apparent from the following description and accompanying drawings forming part of this application.

In the Drawings:

FIG. 1 is a block diagram illustrating one embodiment of a pump-compressor system in accordance with the invention;

FIG. 2 is a cross-sectional view of a combination pump and compressor in accordance with the invention;

FIG. 3 is a plan view of the pump-compressor combination shown in FIG. 2;

FIG. 4 is a cross-sectional view of FIG. 3 taken along the line 4-4 thereof;

FIG. 5 is a cross-sectional view of FIG. 2 taken along the line 55 thereof;

FIG. 6 is a perspective exploded view of the pumpcompressor shown in FIGS. 2 through 5 with the intermediate housing portion being duplicated to show both sides thereof;

FIG. 7 shows a plurality of cross-sectional views of FIG. 3 taken along the lines 7A-7A through 7G7G thereof and illustrating gas and liquid flow within the pump-compressor.

FIG. 8 is an elevational view of the pump-compressor body portion similar to FIG. 7C with the rotor and vanes shown in phantom;

FIG. 9 is an elevational view of the intermediate or control portion similar to FIG. 7D showing the rotor and vanes positioned thereon with portions of the rotor being in section;

FIGS. 10 through 12 are side and end views of a modified form of the intermediate or control portion of the pump-compressor combination according to the invention, and

As previously discussed, this invention involves an improved combination pump-compressor for handling both a liquid and gas simultaneously and to novel and improved fluid circuits particularly useful with the combination pump and compressor. Inasmuch as fluid leakage occurs between the pump and compressor portions of the device the fluid circuits are arranged for the separation of the fluids and produce an output flow of a substantially gas-free liquid and a substantially liquid-free gas. It will also be observed that through the control of the gas pressure, precise liquid flows at pressures above and below atmospheric pressure can be obtained. One form of fluid circuit in accordance with the invention is shown in FIG. I and provides a basic understanding of certain aspects of the invention.

While the pump and compressor are combined within a single body, for convenience they are illustrated separately in FIG. 1 and denoted by the numerals and 11 respectively. The pump 10 includes three inlet ports 12, 13 and 14 and an outlet port denoted by the numeral 15. The compressor 11 includes an inlet or suction port 16, gas flow adjusting means 17 and an outlet 18. Inasmuch as gas can leak into the liquid pump and vice versa leakage is symbolized by the conduits 19, 20, 21 and 22 which are not physical parts of the apparatus. In each of the conduits the darkened portions show the approximate relative proportion of liquid to gas and this applies to all illustrated conduits both actual and symbolic.

Liquid is fed to the primary pump port 12 from a supply tank 23, through conduit 24, anti-flood valve 25 and conduit 26. Liquid under pressure is delivered to the discharge port 15 and thence through conduit 27 to the reservoir 28. Since gas leaks from the compressor to the pump two phase fluid is fed to the reservoir where the gas and liquid are separated. Liquid is then delivered to the reservoir outlet conduit 29 which communicates with the reservoir at a point below the normal liquid level as illustrated. In order to maintain the normal liquid level a feed back conduit 30 communicates with the reservoir at a point above the reservoir outlet and as a consequence a two-phase fluid is fed through conduit 30 to the secondary port 13 of the pump. This secondary port communicates with the pump at a suction point in the pumping cycle spaced from the primary port 12. Thus, the suction at the secondary port is normally less than the suction at the primary port and the liquid being pumped now contains gas both from leakage and the feed back conduit 30.

The gas compressor 11 draws gas into the inlet 16 and discharges both gas and liquid from the outlet 18 through conduit 31 to the cyclone separator 32. Substantially liquid free gas is then delivered to the outlet conduit 33 while a two-phase fluid is fed through the conduit 34 to the tertiary port 14 of the pump. Inasmuch as the pump has a two-phase fluid and the two phase fluid in conduit 34 is under pressure it will enter the tertiary port and contribute to the pump pressure at the outlet port 15. The pressure of the gas delivered to the gas outlet conduit is controlled by the flow control 17 forming part of the compressor. The gas pressure in the reservoir 28 is controlled by a feed back flow control 35 connected to the reservoir by conduit 36 and to the inlet of the compressor by conduit 37. A gas reference pressure applied to control 35 through conduit 38 regulates the flow of gas to and from the reservoir to maintain the pressure in the reservoir constant and therefore the flow of liquid from the reservoir constant.

In the event the pressure should increase in discharge port 15, which will also increase in conduit 27, this increase will open relief valve 39 and permit liquid to flow into conduit 40 coupled in parallel with conduit 26 at pump inlet port 12. Thus the returned liquid or liquid and gas as the case may be is either reprocessed by the pump or returnedto the supply through the anti-flood valve 25. The anti-flood valve functions to open as a result of suction occurring upon operation of the pump and thus prevents flow of liquid from the supply and into the system when the pump is not operated. In the absence of the anti-flood valve, liquid from an elevated supply tank could ultimately flood the entire system and thus create a nuisance and hazard.

With the foregoing arrangement the rates of delivery of both liquid and gas can be precisely and independently controlled without the need for complicated controls, for instance, through the utilization of multiple inlet ports which provide passive control functions, the total time that any port may function can be varied so that relatively large orifices can be used for metering. In the case of the tertiary port 14, which in actual practice communicates with the pump at a point where the volume is diminishing, liquid can nevertheless be admitted since a two-phase fluid is being pumped. The pressure in the reservoir can also be above or below atmospheric pressure or at atmospheric pressure as may be desired. For instance, if the admission of air to the control 35 is restricted the pressure in the reservoir will be maintained below atmospheric pressure while if the flow of air from the reservoir is restricted the pressure will rise above atmospheric pressure.

The preferred pump and compressor for use with the system described above is illustrated in FIGS. 2 through 9 and constitutes a novel and improved rotary vane compressor and pump wherein the pumping and compressing means function in the manner illustrated and described in the aforementioned applications for patent. The combination pump and compressor in accordance with this invention includes a self-contained reservoir and internally arranged conduits which affords a completely integrated, trouble-free unit.

The combination pump-compressor is arranged in three cooperating sections, namely, the main body 41, the intermediate or control section 42 and the reservoir section 43. While the pump-compressor may be used with any suitable combination of gas and liquid depending upon the application, the illustrated apparatus is particularly intended as an air and oil supply for an oil burner and for convenience it will be described in terms of pumping oil and compressing air.

The main body section 41 includes a circular recess 44 housing rotor 45 having slots 46 (FIG. 6) slidably receiving vanes 47. The rotor 45 is eccentrically mounted within recess 44 and is carried by the shaft 48 which extends through an opening 48'in the body 41. As described in the aforementioned applications for patent, air is compressed in the space between the surface of rotor 45 and the wall of recess 44 while oil is pumped by the vanes 47 reciprocating in slots 46. The oil ports communicating with the vane slots are the inlet port 58 (58'), the secondary port 49 which extends through the control section 42, the tertiary port 50 and the outlet port 51 as shown more clearly in FIG. 6. A second outlet port in the form of an annular recess 52 communicates with an outlet opening 52' and passages 54 and 55 as shown in FIG. 7B. The opening 55 opens into the top of the body 41 as shown in .FIG. 6 while the passage 55 opens into the side of the body. One of the openings may be used for gaging the output pressure if desired while the other would be plugged. The opening or bore 56 in the body 41 extends downwardly and receives control valve 57 as shown in FIG. 4. This opening intersects passage 55 which communicates with the oil pump outlet on the high pressure side of the diaphragm 57 of valve 57. A second passage 53 communicates with the low pressure side of the diaphragm 57 and opens into the face 41 of the body 41 for communication with the recess 59 in the cooperating face of control section 42. The recess 59 in turn communicates with openings 60 and 61, the latter receiving oil from the downstream side of the anti-flood valve 62 as will be described. Normally, this valve 57 is in the open position as illustrated in FIG. 4 to permit oil to flow from the downstream side of the anti-flood valve 62 to the oil inlet 58 of the pump. Excess pressure at the pump outlet 53 reacts on diaphragm 57 of valve 57 to close it and prevent the flow of oil from the oil supply to the pump inlet 58.

Oil from a suitable supply is fed to the pump through the inlet 63 on pump section 43 and enters the chamber 64. It then passes through the screen 65 and into a chamber 66 formed between the annular wall 67 and the screen 65. The annular wall 67 defines the reservoir 68 which is partly within the section 43 and partly within the section 42 as will be observed in FIG. 2. Oil from the chamber 66 feeds through a passage 69 in control section 42 and communicates with the upstream side of the anti-flood valve 62. With this arrangement, when the pump is operated suction is applied to passage 60 as previously described so that atmospheric air entering the valve through passage 70 reacts on diaphragm 71 to open the valve and permit oil to flow from passage 69 to passage 60. The valve portion 71a of the anti-flood valve is slidably mounted on shaft 71b so that it can be displaced from its seat either by the action of the diaphragm or by the presence of excess pressure reflected in the conduit or passage 60. With such an arrangement the valve 57 may be a conventional relief or pap valve coupling passages 55 and 58 so that excess oil pressure will be bypassed to the pump inlet and thence through the anti-flood valve 62 to the oil supply.

The oil delivered under pressure from the pump outlet passage 51 as viewed in FIG. 6 flows through that passage which communicates with reservoir 68 and is then discharged through the outlet 71. Oil feed back to the pump to maintain a selected level within the reservoir is accomplished by passage 49 extending from the reservoir through control section 42 to form the secondary inlet to the pump.

The air supply is provided by an air inlet 72 communicating with passage 73 and the recess 74 on the pump side of the control section 42 as viewed in FIGS. 4, 6, 7 and 9. Compressed air is delivered to the outlet recess 75 which communicates with the passage 76 in the pump section 41 and enters the large air outlet bore 54 which forms a cyclone separator. Thus oil which leaks into the air compressor portion of the pump is separated from the air and feeds into passages 77 and 78 as viewed in FIG. 7A. A passage 78 communicates with the tertiary inlet 50 to permit oil and some air to feed into the oil supply. Communication between the air in reservoir 68 and the air compressing circuit is effected by the passage 79 which intersects a passage 80 extending inwardly into the control section 41 from the rear side 81 thereof and communicates with the air inlet passage 72. A needle valve generally denoted by numeral 82 controls the flow of air to the compressor inlet 73. Since a two-phase fluid consisting of oil and air is fed to the reservoir, air pressure in the reservoir determines the rate of delivery of oil from outlet 71. Control of the oil delivery rate can then be controlled by needle valve 82 which recirculates air from the reservoir to the air inlet. Control of the air outlet pressure from outlet 54 is effected by the needle valve 83 disposed within an opening 84 in the control section 42. This valve controls communication between passages 85 and 86 which open into the face of control section 42 which adjoins the body section 41 and communicates with the air compressing chamber surrounding the rotor 45. Thus both the output air pressure as well as the output oil pressure are readily controlled by the two needle valves.

The combination pump-compressor described above functions in the same manner as the system described in connection with FIG. 1 except for operation of the valve 57 as shown in FIG. 4. It is evident, however, that the downstream side of the anti-flood valve 62 can be connected directly to the inlet 48' and that a conventional relief valve be substituted for the valve 57 so that excess high pressure be bled to the pump inlet as described in connection with FIG. 1. It is also evident that various modifications may be made in the mode of operation of the pump-compressor circuitry to accomplish a variety of modes of operation. For instance, other modes of air pressure control may be used for the reservoir such as presure relief valves, the anti-flood valve may be replaced with an electrically controlled valve and a pressure sensitive switch actuated by the output oil pressure so that the valve opens when the pump drive motor is actuated and will close if excess pressure is developed in the system. It will also be observed that by reason of the oil feed back loops, that the pump remains primed at all times. Other modes of control of output air pressure may also be utilized and oil can be delivered at pressure above, at or below atmospheric pressure.

In view of the foregoing description it is evident that the novel and improved pump-compressor and the novel and improved fluid circuitry provide a gas pumping and liquid compressing system that is characterized by its efficiency, dependability, ease of adjustment and the precise delivery of selected flows of both liquid and gas. Moreover, liquids and gases other than oil and air may be handled with equal facility.

FIGS. 10, 11 and 12 are views of a modified control section denoted herein by the numeral 42A in order to lower the oil reservoir so that it is below the atomozing nozzle of an oil burner when the pump-compressor is required to supply both oil and air to the nozzle. For this purpose the control section 42a is provided with a depending hollow housing 90 having an oil outlet 91, a passage 92 coupling the bottom of the reservoir 68 with the reservoir 90, and a return line 93 coupled to the recycle passage 49. In this way the oil level in the housing 90 will be controlled in the same manner previously described except that the new reservoir is below the level of the nozzle.

The adjustable gas flow control 35 as shown in FIG. 1 can be designed to maintain the gas ballast pressure in reservoir 28 at a value slightly below ambient pressure, at ambient pressure, or slightly above ambient pressure, when conduit 38 is open to the ambient atmosphere. If conduit 38 is connected to the gas discharge port 31, considerably higher gas ballast pressures can be maintained in reservoir 28. This may necessitate a shift in the location of tertiary port 14 in FIG. 1 (tertiary port 50 in FIG. 6). Should the ballast pressure be set higher than the gas discharge pressure, it becomes necessary to switch the relative positions of ports 14 and 13 (port 49 in FIG. 6) so that oil plus some gas can drain from cyclone separator 32 into the oil suction port, which will now be the secondary port. Oil plus some gas overflowing from the reservoir through conduit 30 will now go to the tertiary port 14 (50).

While only certain embodiments of the invention have been illustrated and described it is apparent that alterations, changes and modifications may be made without departing from the true scope of the invention as defined by the appended claims.

What is claimed is:

1. Apparatus for supplying a liquid to a gas-ballasted reservoir maintained at a predetermined pressure, and for supplying a compressed gas at a predetermined pressure, comprising a lilquid pump having a plurality of individual inlets at successive phases of the pumping cycle and at least one outlet, a gas compressor having an inlet and an outlet, means including a control valve for feeding liquid from a supply to a first inlet to said pump, a reservoir for receiving and retaining liquid at a selected level therein, a liquid inlet in said reservoir above said selected level, means coupling the last said inlet to the outlet of said pump, a first liquid outlet in said reservoir below said selected liquid level, an opening in said reservoir above said liquid level for the flow of gas therethrough whereby said reservoir will contain gas above said liquid, a second liquid outlet in said reservoir at said selected liquid level and means coupling the last said outlet to another of said pump inlets whereby a two-phase fluid containing both gas and liquid will be fed to said pump and said pump outlet will contain a two-phase fluid with the gas and liquid separating upon entering said reservoir, means supplying a gas to the inlet of said compressor, means including a gas control coupling said compressor to the opening in said reservoir to control the 'gas pressure in said reservoir, a liquid and gas separator coupled to the outlet of said compressor to remove liquid which may be contained in gas flowing from the reservoir to the compressor inlet means for feeding the liquid which may contain gas from said separator to a pump inlet and a compressed gas outlet on said separator.

2. Apparatus according to claim 1 including a pressure relief valve interconnected between said pump outlet and said first inlet.

3. Apparatus according to claim 1 wherein said control vavle is operable to open in response to suction at said pump inlet.

4. Apparatus according to claim 1 wherein said pump includes at least three inlets consisting of a primary inlet, a secondary inlet and a tertiary inlet and wherein liquid from said supply is fed to said primary inlet, the two-phase fluid from said reservoir is fed to said secondary inlet and the liquid from said separator is fed to said tertiary inlet.

5. Apparatus according to claim 1 wherein said gas control comprises a valved conduit coupling said opening with the compressor inlet and a second valved conduit coupling said opening with a gas supply at a selected reference pressure.

6. Apparatus according to claim 1 wherein said compressor comprises a housing having a recess therein, a slotted rotor eccentrically positioned for rotation within said recess and vanes slidably engaging the slots on said rotor, said compressor inlet and outlet communicating with the space surrounding said rotor whereby gas drawn into said space is compressed and delivered to said outlet and wherein said pump comprises the inner portions of said vanes and said slots which form chambers each of which increases from a minimum volume during each rotation of the rotor, one of said liquid inlets communicating with each of said chambers as it starts to increase from a minimum volume, a secondary inlet communicating with each of said chambers prior to attainment of maximum volume and a tertiary inlet communicating with each of said chambers after attainment of maximum volume and said liquid outlet communicates with said chambers as they approach minimum volume.

7. Apparatus according to claim 6 wherein said housing includes said reservoir.

8. Apparatus according to claim 6 wherein at least part of said reservoir is disposed below said housing.

9. Apparatus according to claim 6 wherein said gas compressor includes at least two ports, one communicating with the space between said rotor and said recess at a point angularly spaced from said gas inlet and prior to the point of maximum outward displacement of the vanes and the other communicating with said space at a point after said point of maximum outward displacement of the vanes and valving means coupling the last said ports to control the output gas pressure of said pump.

10. Apparatus according to claim 6 wherein gas will leak from said compressor to said pump during the intake of liquid thus producing a two-phase fluid at all times within said pump and liquid leaking into said compressor is discharged therefrom and separated and removed from said gas by said separator.

11. Apparatus for supplying liquid at a predetermined rate and gas at a predetermined pressure comprising a housing formed of at least three portions secured one to the others to form a unitary structure, the first housing portion having a recess in one face thereof, an opening extending from the base of said recess through said first housing section for rotatably accommodating a shaft positioned eccentrically relative to said recess, a rotor carried by said shaft and disposed within said recess, said rotor having radially disposed slots slidably receiving vanes, said vanes reciprocating within said slots during rotation of said rotor, a second housing section having opposing faces with one face overlying and sealed to the face of the firsthousing section to close said recess, two sets of ports in said housing sections with one set communicating with the space between said rotor and the peripheral wall of said recess for the intake and discharge of gas and the other set of ports communicating with the chambers formed between the inner ends of said vanes and the bottom portions of said slots for the intake and discharge of liquid, the third housing portion having a face overlying the other face of said second housing portion, the last faces being sealed one to the other with at least one of the last said faces having a recess therein forming a fluid reservoir, liquid and gas inlet passages in said housing and communicating with certain of said sets of ports, liquid and gas outlets in said housing communicating with said reservoir and said gas discharge port and passages within said housing connecting certain of said set of liquid ports to said reservoir and said gas outlet port.

12. Apparatus according to claim 11 wherein said housing includes a liquid-gas separator communicating with a said gas discharge port having a liquid outlet and a gas outlet and wherein the last said liquid outlet is coupled with one of said other set or ports.

13. Apparatus according to claim 12 wherein said gas intake and discharge ports are carried by said one face of said second housing portion, said second housing portion including a gas inlet communicating with the last said intake port and said first housing portion including a passage extending from said separator to the face of said first housing portion and communicating with said gas discharge port.

14. Apparatus according to claim 13 wherein said set of ports comprises first, second and third inlet ports and two outlet ports with said first and third inlet ports and one outlet port being formed in the base of the recess in the first housing portion and said second inlet port and the other outlet port being formed in said one face of said second housing portion.

15. Apparatus according to claim 14 wherein said second inlet port constitutes an opening extending between the faces of said second housing portion and communicating with said reservoir at a point spaced from the bottom thereof to control the liquid level in the reservoir.

16. Apparatus according to claim 15 wherein said third inlet port communicates with the liquid outlet on said separator, said first inlet port communicates by way of passages in the first and second body portions with an anti-flood flow valve carried by said second body portion and operable to open in response to suction at said pump inlet, said third body portion includes a liquid inlet chamber and a liquid inlet, said second body portion includes a passage coupling said inlet chamber with said anti-flood valve, said other outlet port comprising a passage extending through said second housing portion and communicating with said reservoir above said liquid level therein, and a liquid outlet communicating with said reservoir below said liquid level.

17. Apparatus according to claim 16 wherein said second body portion includes a valve coupling said gas inlet with the last said passage.

18. Apparatus according to claim 17 wherein said one face of said second housing portion includes two 10 gas pressure control ports and a valve coupling said ports one to the other.

19. The method of pumping a liquid and compressing a gas to deliver liquid at a predetermined rate and gas at a predetermined pressure comprising the steps of feeding liquid under pressure from a supply to a reservoir containing both liquid and gas, feeding back a two phase fluid containing liquid and gas, from said reservoir to said pump, the relative percentages of liquid and gas in said fed back two phase fluid controlling the rate of liquid fed from said supply to control and maintain a selected liquid level in said reservoir whereby said pump processes a two-phase fluid and feeds the twophase fluid to said reservoir, feeding gas to said compressor for delivery of a compressed gas, coupling said reservoir to a gas supply and to said compressor and controlling the flow of gas into and out of said reservoir to maintain a selected gas pressure therein and controlling the rate of compression of said gas and effecting delivery of said liquid and gas to the place of use.

20. The method according to claim 19 including the step of separating gas and liquid from said compressor and feeding said liquid to said pump at a pressure point in the pumping cycle.

21. The method according to claim 20 including the step of interrupting the flow of liquid to said pump when the pumping operation is terminated and feeding back pumped liquid to the pump inlet in the event liquid pressure exceeds a selected magnitude. 

1. Apparatus for supplying a liquid to a gas-ballasted reservoir maintained at a predetermined pressure, and for supplying a compressed gas at a predetermined pressure, comprising a lilquid pump having a plurality of individual inlets at successive phases of the pumping cycle and at least one outlet, a gas compressor having an inlet and an outlet, means including a control valve for feeding liquid from a supply to a first inlet to said pump, a reservoir for receiving and retaining liquid at a selected level therein, a liquid inlet in said reservoir above said selected level, means coupling the last said inlet to the outlet of said pump, a first liquid outlet in said reservoir below said selected liquid level, an opening in said reservoir above said liquid level for the flow of gas therethrough whereby said reservoir will contain gas above said liquid, a second liquid outlet in said reservoir at said selected liquid level and means coupling the last said outlet to another of said pump inlets whereby a two-phase fluid containing both gas and liquid will be fed to said pump and said pump outlet will contain a two-phase fluid with the gas and liquid separating upon entering said reservoir, means supplying a gas to the inlet of said compressor, means including a gas control coupling said compressor to the opening in said reservoir to control the gas pressure in said reservoir, a liquid and gas separator coupled to the outlet of said compressor to remove liquid which may be contained in gas flowing from the reservoir to the compressor inlet means for feeding the liquid which may contain gas from said separator to a pump inlet and a compressed gas outlet on said separator.
 2. Apparatus according to claim 1 including a pressure relief valve interConnected between said pump outlet and said first inlet.
 3. Apparatus according to claim 1 wherein said control vavle is operable to open in response to suction at said pump inlet.
 4. Apparatus according to claim 1 wherein said pump includes at least three inlets consisting of a primary inlet, a secondary inlet and a tertiary inlet and wherein liquid from said supply is fed to said primary inlet, the two-phase fluid from said reservoir is fed to said secondary inlet and the liquid from said separator is fed to said tertiary inlet.
 5. Apparatus according to claim 1 wherein said gas control comprises a valved conduit coupling said opening with the compressor inlet and a second valved conduit coupling said opening with a gas supply at a selected reference pressure.
 6. Apparatus according to claim 1 wherein said compressor comprises a housing having a recess therein, a slotted rotor eccentrically positioned for rotation within said recess and vanes slidably engaging the slots on said rotor, said compressor inlet and outlet communicating with the space surrounding said rotor whereby gas drawn into said space is compressed and delivered to said outlet and wherein said pump comprises the inner portions of said vanes and said slots which form chambers each of which increases from a minimum volume during each rotation of the rotor, one of said liquid inlets communicating with each of said chambers as it starts to increase from a minimum volume, a secondary inlet communicating with each of said chambers prior to attainment of maximum volume and a tertiary inlet communicating with each of said chambers after attainment of maximum volume and said liquid outlet communicates with said chambers as they approach minimum volume.
 7. Apparatus according to claim 6 wherein said housing includes said reservoir.
 8. Apparatus according to claim 6 wherein at least part of said reservoir is disposed below said housing.
 9. Apparatus according to claim 6 wherein said gas compressor includes at least two ports, one communicating with the space between said rotor and said recess at a point angularly spaced from said gas inlet and prior to the point of maximum outward displacement of the vanes and the other communicating with said space at a point after said point of maximum outward displacement of the vanes and valving means coupling the last said ports to control the output gas pressure of said pump.
 10. Apparatus according to claim 6 wherein gas will leak from said compressor to said pump during the intake of liquid thus producing a two-phase fluid at all times within said pump and liquid leaking into said compressor is discharged therefrom and separated and removed from said gas by said separator.
 11. Apparatus for supplying liquid at a predetermined rate and gas at a predetermined pressure comprising a housing formed of at least three portions secured one to the others to form a unitary structure, the first housing portion having a recess in one face thereof, an opening extending from the base of said recess through said first housing section for rotatably accommodating a shaft positioned eccentrically relative to said recess, a rotor carried by said shaft and disposed within said recess, said rotor having radially disposed slots slidably receiving vanes, said vanes reciprocating within said slots during rotation of said rotor, a second housing section having opposing faces with one face overlying and sealed to the face of the first housing section to close said recess, two sets of ports in said housing sections with one set communicating with the space between said rotor and the peripheral wall of said recess for the intake and discharge of gas and the other set of ports communicating with the chambers formed between the inner ends of said vanes and the bottom portions of said slots for the intake and discharge of liquid, the third housing portion having a face overlying the other face of said second housing portion, the last faces being sealed one to the other with at least one of the last said faces having a recess therein forming a fluid reservoir, liquid and gas inlet passages in said housing and communicating with certain of said sets of ports, liquid and gas outlets in said housing communicating with said reservoir and said gas discharge port and passages within said housing connecting certain of said set of liquid ports to said reservoir and said gas outlet port.
 12. Apparatus according to claim 11 wherein said housing includes a liquid-gas separator communicating with a said gas discharge port having a liquid outlet and a gas outlet and wherein the last said liquid outlet is coupled with one of said other set or ports.
 13. Apparatus according to claim 12 wherein said gas intake and discharge ports are carried by said one face of said second housing portion, said second housing portion including a gas inlet communicating with the last said intake port and said first housing portion including a passage extending from said separator to the face of said first housing portion and communicating with said gas discharge port.
 14. Apparatus according to claim 13 wherein said set of ports comprises first, second and third inlet ports and two outlet ports with said first and third inlet ports and one outlet port being formed in the base of the recess in the first housing portion and said second inlet port and the other outlet port being formed in said one face of said second housing portion.
 15. Apparatus according to claim 14 wherein said second inlet port constitutes an opening extending between the faces of said second housing portion and communicating with said reservoir at a point spaced from the bottom thereof to control the liquid level in the reservoir.
 16. Apparatus according to claim 15 wherein said third inlet port communicates with the liquid outlet on said separator, said first inlet port communicates by way of passages in the first and second body portions with an anti-flood flow valve carried by said second body portion and operable to open in response to suction at said pump inlet, said third body portion includes a liquid inlet chamber and a liquid inlet, said second body portion includes a passage coupling said inlet chamber with said anti-flood valve, said other outlet port comprising a passage extending through said second housing portion and communicating with said reservoir above said liquid level therein, and a liquid outlet communicating with said reservoir below said liquid level.
 17. Apparatus according to claim 16 wherein said second body portion includes a valve coupling said gas inlet with the last said passage.
 18. Apparatus according to claim 17 wherein said one face of said second housing portion includes two gas pressure control ports and a valve coupling said ports one to the other.
 19. The method of pumping a liquid and compressing a gas to deliver liquid at a predetermined rate and gas at a predetermined pressure comprising the steps of feeding liquid under pressure from a supply to a reservoir containing both liquid and gas, feeding back a two phase fluid containing liquid and gas, from said reservoir to said pump, the relative percentages of liquid and gas in said fed back two phase fluid controlling the rate of liquid fed from said supply to control and maintain a selected liquid level in said reservoir whereby said pump processes a twophase fluid and feeds the two-phase fluid to said reservoir, feeding gas to said compressor for delivery of a compressed gas, coupling said reservoir to a gas supply and to said compressor and controlling the flow of gas into and out of said reservoir to maintain a selected gas pressure therein and controlling the rate of compression of said gas and effecting delivery of said liquid and gas to the place of use.
 20. The method according to claim 19 including the step of separating gas and liquid from said compressor and feeding said liquid to said pump at a pressure point in the pumping cycle.
 21. The method according to claim 20 including the step of interruPting the flow of liquid to said pump when the pumping operation is terminated and feeding back pumped liquid to the pump inlet in the event liquid pressure exceeds a selected magnitude. 